Autologoff (ALOT)

Autologoff can terminate a session with IMS for a terminal that has been signed off for an allotted period. After an allotted time, the terminal is automatically logged off.

The system programmer sets this time on any of the following:
  • On the ALOT (auto logoff time) parameter in the DFSPByyy member
  • On the logon descriptor that is used to create the session control blocks
  • On the EXEC parameter at initialization
If more than one allotted time value exists, the following criteria are used to determine which allotted time value to use:
  • If the ALOT value is specified on the logon descriptor, this allotted time value is used.
  • If the logon descriptor does not specify a valid allotted time value, the time value specified in the DFSPByyy member is used.
  • If the DFSPByyy member does not specify an allotted time value, the default value of 1440 is used.
  • If the value on the DFSPByyy member is not valid, the default value of 10 is used.

You can specify ALOT=1440 on the logon descriptor for a 3600/Finance, SLU-P, or ISC terminal in order to specify that no autologoff is desired. The system default value for these devices is 1440. Logon descriptors created for ISC terminals should have ALOT=1440 specified to show that autologoff should not occur. The Logon exit routine (DFSLGNX0) can override the ALOT value during logon, even when the control block structure exists.

The values for the allotted time specified on the ALOT parameter in the DFSPByyy member are:
ALOT = 0
The terminal is logged-off immediately when no signon is in effect. This specification is normally used in terminal sessions when the user is signed-on automatically during the logon process. During autologon, signon data can be provided in one of the following ways:
  • Signon data supplied by the IMS /OPNDST command
  • Signon data supplied by logon user data (BIND)
  • Signon data supplied by logon exit (DFSLGNX0)

There are two modes of operation for using ALOT=0, either of which can be set using the DFSINTX0 User Initialization Exit parameter list.

In default mode, when signon errors are encountered, the session is automatically signed off and then logged off; no message is sent. If you do not supply the DFSINTX0 exit, or you supply the exit and indicate default mode for ALOT=0, then signon data must be supplied during the logon process. All of the following error conditions result in automatic logoff:

  1. A non-signon, or errors detected during signon or input processing, result in immediate logoff.
  2. /SIGNOFF results in immediate logoff.
  3. /SIGNON signs off the current user and signs on a new user. However, errors encountered during the signon process, such as detection of an incorrect or expired password, result in immediate logoff.
Restriction: Default mode should not be used for interactive terminal sessions that require a response to the DFS3649 message; these sessions will not wait for input signon and will logoff immediately.

In alternate mode, when signon errors are encountered, the session is automatically signed off, a message is sent and the session is logged off. Signon data can be supplied but is not required. All of the following error conditions result in automatic logoff:

  1. A non-signon error detected during input processing results in immediate logoff.
  2. No signon data has been provided by the logon serrated (BIND) or the Logon Exit (DFSLGNX0).
  3. A /SIGNOFF, or errors resulting from a /SIGNON, cause message DFS3649(A) (Signon Required) to be sent, and a fixed ten-minute timer set to wait for a new signon. If no signon occurs during that interval, then the session is logged off.
ALOT = (10 - 1439)
The session is terminated after the allotted number of minutes has elapsed without a signed-on user.
ALOT = 1440
The session is never automatically terminated. This is equivalent to not having autologoff.